Right,
i opened a bottle of wine and stripped the saragosa to look into this main shaft play.
The plastic spacer/cap was present at the bottom of the worm gear thanks Hon-SU and I checked the diagram to ensure all parts were present and counted for, so I am confident that its all ok. Greased it up and put it back together, checked the play - still 2mm. Bugger
Had a think about it and decided to give it another go. Pulled out the work gear and the main shaft, and noticed that the plate which retains both shafts from falling out the bottom of their carrier was bent!! only a tiny bit, but i straightened/flattened it out, put it back in and hey presto play is back down to 1mm in the main shaft! hooray!
sorry i didnt take pics, I was a man on a mission. i did take before and after line lay photos which ive attached
